#4 AJ Styles
Years before becoming a global superstar in WWE, AJ Styles competed in WCW for a brief period of time. Styles spent the majority of his early career wrestling with indie promotions. His incredible athleticism hadn't gone unnoticed, and World Championship Wrestling offered him a contract in early 2001. This was a time when WCW was desperately trying to create new stars and was on its last legs.
Styles was put in a tag team called Air Raid alongside Air Paris, who had worked with Styles before coming to WCW. The duo have appeared on three occasions on WCW's B-show, Thunder. Later, they were eliminated in the first round of a tournament to determine the first-ever Cruiserweight Tag Team Champions. WCW was bought off weeks later and Styles went on to carve a niche for himself in TNA and eventually WWE, where he became a legit main eventer and multi-time WWE Champion.
Styles is an industry veteran who plied his trade in promotions around the world before getting his due with WWE.